Police officers and interventional cardiologists have something heavy in common: Both don metal to protect them from the hazards of their professions.

But while cops will wear bulletproof vests as long as crooks carry guns, new technology now in use at UC San Diego’s Thornton Hospital in La Jolla takes docs out of the line of fire.

A $500,000 robot allows cardiologists to shed the heavy leaded aprons, jackets and thyroid shields that many studies show cause back problems and offer incomplete protection from X-rays used to guide the catheters that restore blood flow in blocked arteries.

The university is the first in the state, and one of 15 nationwide, to install the robotic catheterization system made by Massachusetts-based Corindus Vascular Robotics. The device occupies one of four catheterization suites at UC San Diego Health System Sulpizio Cardiovascular Center.

On a recent morning, Dr. Ehtisham Mahmud used the machine to push a thin catheter tipped with a bit of wire mesh called a stent into a patient’s coronary artery. The interventional cardiologist, who is also the center’s co-director, performed most of the operation sitting down at a computer console, his hands on a set of electronic controls, his eyes on a real-time X-ray image of the procedure in progress.

Twitching a pair of joysticks caused the robot to push or pull the long wire into or out of the blood vessel. It also allowed Mahmud to rotate the device intricately and measure the length of lesions and stents with new levels of precision.

He sat comfortably wearing blue hospital scrubs, a much lighter get up than he would have worn had he been operating in any of the hospital’s traditionally-equipped facilities.

“Usually, I’ve got 25 pounds on my back. For a short case, I’m getting five, seven, eight minutes of fluoroscopy radiation. A really complicated case can take up to three hours, and I’m getting closer to, maybe, an hour,” Mahmud said.

After 17 years of doing procedures covered in lead shielding, the doctor said getting to sit down and work without the weight has been ... relaxing.

“When I do two or three cases in that room, I feel like I didn’t even work,” he said.

The U.S. Food and Drug Administration greenlighted the robotic system, called the CorPath 200, in 2012 after its manufacturer showed a 97.6 percent success rate in clinical trials with 25 patients and proved that the device could reduce radiation exposure by 95 percent.

UC San Diego began using the machine in December. Wider adoption of the system will come down to more studies with larger numbers of participants that show the robot is as effective as, or more effective than, existing technology, said Dr. Charles Chambers, president-elect of the Society for Cardiovascular Angiography and Interventions.

“In the end, it all comes down to patient outcomes,” he said.

Understanding risks

The physical strains associated with a career in angioplasty have been getting increasing amounts of scrutiny from medical researchers. In fact, the problems are seen as serious enough to merit their own multi-specialty working group that is studying the stresses put on these cardiologists and their teams.

In 2010, the group published a paper in the Journal of Radiology Nursing that cited six recent studies that documented “what appears to be an epidemic of orthopedic injuries” related to a career spent wearing heavy lead-lined protective gear.

In one study from 2004, for example, nearly half of 424 respondents to a survey by the Society of Cardiac Angiography and Interventions reported spine problems, nearly double the rate observed in the overall adult population. A quarter of those surveyed “reported problems related to their hips, knees or ankles.” The authors wrote that in some cases, these orthopedic problems had ended careers.

The effects of receiving regular doses of X-ray radiation over 20 to 30 years are less clear. The 2010 paper said while there are plenty of studies showing that increased exposure can lead to higher rates of cataracts, cancers and possibly other diseases, “no firm conclusions could be reached regarding increased rates of radiation-associated diseases.”

But researchers are starting to look more closely at cancer in this population of medical specialists. A 2013 paper in the American Journal of Cardiology found that of 26 cases of brain cancer in longtime cardiologists and radiologists, 22 of them occurred on the left side of the head.

That paper, written by Dr. Ariel Roguin, head of interventional cardiology at Rambam Medical Center in Haifa, Israel, notes that the left side is “known to be more exposed to radiation and least protected by traditional shielding.”

More research needed

Chambers, with the Society for Cardiovascular Angiography and Interventions, said while the paper’s results are interesting, they are also anecdotal.

“It’s not as scientific reporting as we would like, but the findings are disconcerting,” Chambers said.

He said work is underway to do a much larger retrospective study of many more doctors to see if there is deeper and broader evidence of high cancer rates among cardiologists regularly exposed to radiation in the course of their daily duties.

“It’s really kind of amazing that we have such excellent databases for patient outcomes but not nearly as much data for physicians,” Chambers said.

And it’s not as if the industry has been ignoring the radiation-exposure problem. Advances have been made, Chambers said, in shielding and other radiation-limiting procedures. The ability to take the doctor away from the bedside, he said, brings obvious benefits.

“If you’re not wearing lead. If you’re sitting down somewhere where there is no dose, those are obvious benefits,” he said.

Chambers also noted that doctors are only one part of larger angioplasty teams. Other team members, he noted, are also exposed.

“It’s important to see that there are still other staff walking around the room wearing lead,” he said.